Stranded conductor



July 21, 1936.

H. HORN STRANDED CONDUCTOR Filed Jan. 23, 1934 Patented Jul 21, 1936 i i 2,048,450

UNITED STATES PATENT OFFICE Application January 2:, 1034, Serial s... 707,964 In Germanylannary 24, 1933 china. (cl. ire-is) This invention relates 'to a method of manuinstance, be produced by making individual facture of stranded conductors of the -so-called wires, for instance all wires I of a thermo-plastic "re-entrant 7 type. A conductor of the "rematerial instead of making all the wires of metal entrant type". may bedeflned asa stranded conwhich is conducting. However, other methods I ductor in which each one of the wires of which of stranding are to be preferred, as will hereinit is composed changes its position in the cross after bereferred to. If a strandedconductor with section oi the conductor, in such a manner that thermo-plastic layers interposed therein accordit passes in a regular sequence from the centre ing to the invention is subjected to a drawing or of the cross section of the conductor to the outer rolling process and heat is simultaneously apperiphery, from which it returns again to the plied'thereto, the strands consisting of thermo- 10 centre. The individual wires are surrounded by plastic material will soften, and owing to the an insulatingoxide layer or a thin layer of lacgaps thereby produced, it will be possible to quer. Such stranded conductors have the advanimpart to the stranded conductor a higher filling tage that even when traversed by currents of factor withouta greater expenditure in'mechanill high'frequency the current density'jis uniform in ,cal energy.

all parts or the cross section of the conductor Instead of using two conductors with one and thelatter is therefore free from the skin strand of thermo-plastic material to form a effect which increases the resistance. Such constranded element of a higher order, as shown in ductors are thus suitable for the transmission of Figure 1, use is preferably made or a larger numcurrents of high frequency and may, for instance. berof .individual conductors, for instance five of 20 be emp oyed 8- h l t in cable! intended fol, six, which are stranded together around a core flfiquencmh I of the'rmo-plastic. material. However, other In the W W drawinsz modes of stranding a're possible in which a m 1 1111mm!!! one method 01 stranded' conductor according to the invention 5 conductors accordins o the invention is rendered suitable iorv rolling or drawing, by 2 m n v illustrates a second new inserting between the stranded elements thermo- .I'isur 3 fill-lamb & third m h Ind plastic profile strands whichare rendered plastic P181118 {111mm I mm under the action of heat and chan e the me- 111 68 1": 3 t in the ed m rigidity of the stranded conductor in w nefernngtorigurelthreesingleconducton m w 5 Md It has, for instance, been found that the evenm a i g able space can be especially well utilized by a strand of higher or er three 0 wh imag method of mama which lsimusmted turn the! ure 2. Three stranded elements .II are laid 8F be mm mm aroundacentral wire ll, each of which stranded 0 m tf 0 elements ii consists of a core of thermo-plastic m m: a Etr snded condugir 11:: 12d W J W bemm'edbm "mm sui fa ii l fiethod of stranding is illusmieetingthecompetely stranded conductor to-a 3 six profile strands." of 40 drawing or rolling process. Asaresult oithe m are laid around we m the we minimum mm was there are laid six further stranded elements, have tc g g g x g fi 1? d '3 u each of which consists of a core of thermo-piastic conductor and increases its cost of manufacture. 11, Round which 81! Individual w e 28 According to the invention, during h havebeen stranded. Thus the whole of the iscture of the stranded conductonroaie strands Med conductor r y o t ined mprises of a' thermoplastic material are inserted at suitthirty-seven conducting wires. able places between the individual'stranded ele- In order toproduce a conductor of more thane1 50 inents and are stranded therewith. The therev n wire three or six stranded e- 'moplastic material has to be 'sufllciently solid mente may be laid around a wntral wire, each .at ordinary temperature to withstand the meof which stranded elements consists of a strucchanicalstressesofthestranding. Astr'anded ture,snchasshowninFis 2or3. s5 conductor according to-the invention may, for The emnpietely stranded conductor is heated 5 and is drawn by rolling or application of pressure.

Figure 4 is a cross section through a stranded conductor according to Figure 3 after it has been subjected to a rolling process. The thermo-plastic material-has, as will be seen, filled up completelythe spaces between the conducting wires, thus serving at the same time as an insulation between the wires. If a stranded conductor built up as hereinbefore described, is used for deep sea submarine cables, the further advantage is attained that the thermo-plastic material serves at the same time as a pressure-equalizing means.

The profile strands used according to the present invention, may consist of any thermo-plastic insulating material used in the electrical art, for instance guttapercha, Paragutta", balata etc. Especially advantageous is polystyrol, since this material can be drawn into rigid strings or bands and in addition thereto, it possesses especially good electrical properties.

Further, mixtures of polystyrcl, with guttapercha, balata, Paragutta or the like, are used for the profile strands.

Instead of using thermo-plastic profile strands as hereinbefore described, according to a further modification of the invention, use is made of an intermediate layer of a soluble substance, so that instead of subjecting the stranded conductor to heat treatment, it can be treated by means of a solvent. For instance, it is possible to dissolve intermediate layers of guttapercha before the rolling or drawing process, by means of heme].

What I claim is: v

1. A method of manufacturing a high frequency stranded conductor of the type in which each strand is insulated from the next, and the strands change relative positions to minimize skin eiiect, consisting in inserting profile strands of an insulating thermoplastic material between the stranding elements of the stranded conductor and stranding them therewith, softening the said profile strands after the stranding and subjecting the stranded conductor to pressure in such a way that the profile strands are distributed between the stranding elements.

2. A method of manufacturing a high fre-' quency stranded conductor of the type in which each strand is insulated from the next, and the stranding them therewith, softening the said,

profile strands by heat after the stranding and subjecting the stranded conductor to pressure in such a way that the profile strands are distributed between the stranding elements.

3. A method of manufacturing a high frequency stranded conductor of the type in which I each strand is insulated from the next, and the strands change relative positions to minimize skin effect, consisting in inserting profile strands of an insulating soluble material between the stranding elements of the stranded conductor and stranding them therewith, softening the said profile strands by means of a solvent after the stranding and subjecting the stranded conductor to pressure in such a way that the profile strands are distributed between the stranding elements.

4. A method of manufacturing a high frequency stranded conductor of the type in which each strand is insulated from the next, and the strands change relative positions to minimize skin efiect, consisting in stranding around a central core a $0 plurality of strands, each comprising a core of thermoplastic material around which there is stranded a layer of conducting wires, softening all the said profile strands, after the stranding of the strands around the said central core, and subjecting the entire stranded conductor to prasure in such a way that the profile strands are distributed between the stranding elements.

5. A method of manufacturing a high frequency stranded conductor of the type in which each 39 strand is insulated from the next, and the strands change relative positions to minimize skin eifect, consisting in inserting profile strands of polystyrd! between the stranding elements of the stranded conductor and stranding them therewith, softening the said profile strands of polystyrol after the stranding, by heat, and subjecting the stranded conductor to pressure in such a way that the profile strands are distributed between the stranding elements.

6. A method of manufacturing a high frequency stranded conductor of the type in which each strand is insulated from the next, and the strands change relative positions to minimize skin efiect, consisting in inserting profile strands of polystyrol mixed with insulating thermoplastic material between the stranding elements and stranding them therewith, softening the said profile strands of polystyrol mixed with insulating thermoplastic material after the stranding, by heat, and subjecting the stranded conductor to pressure in such a way that the profile strands are distributed between the stranding elements.

HEINZ HORN. 6d 

